The present invention relates to an anti-theft device for objects having portions which can be surrounded by straps or the like.
It is known that anti-theft devices provided with a component which is adapted to be detected if it is immersed in an electromagnetic field normally generated in the presence of a guided exit of the shop or business concern in which the anti-theft devices are adopted, are currently increasingly widespread.
These devices are rigidly coupled to the object to be protected against theft and are separated from it by breaking or by removal by means of special tools, normally when the object is regularly purchased and before the purchaser leaves the shop.
Such devices are generally characterized in that they comprise a strap which is adapted to close like a noose on an application portion of the object to be protected against theft.
The strap is provided with a container for a device which is excitable and therefore detectable in the presence of electromagnetic fields: the strap extends with two portions from the container of the excitable device, namely a rack-shaped first portion with teeth having a triangular cross-section and a second portion which instead supports an anti-theft device composed of a box-like expanded region which is provided with a through hole and accommodates an elastic tab which is shaped complementarily to the rack of the first portion.
Once the first portion of the strap is inserted into the second one, the rack-like portion irreversibly engages the tab, stably fixing the container that accommodates the excitable device to the object of application.
These devices have drawbacks, including limited versatility.
The length of the portion of the strap that supports the box-like expanded region with a through hole in fact determines the minimum perimeter of the portion of the object to be coupled.
The length of the rack-like portion instead determines the maximum perimeter.
Moreover, in the internal part of the strap there are protrusions or studs which do ensure the locking of the device in some cases but hinder its use in others, because they stiffen the strap.
Still further, in some applications the device moves, making it difficult to use for demonstration purposes the product to which the device is connected.